More than three quarters of bill-payers living in rented accommodation have never switched energy supplier, a poll has found.
One in five tenants (20%) said they were not aware it was possible to switch to another energy company, and 77% had not switched their electricity supplier and 74% had not switched their gas, according to the latest data from Ofgem's 2014 Consumer Engagement Survey.
The regulator said the findings highlighted the "sheer lack of awareness" among tenants of their rights to shop around for the best deal, with just 26% of renters ever switching gas supplier compared with 47% of homeowners.
Ofgem said that although renters often thought they had to accept the energy suppliers already in place when they moved in, this was very rarely the case.
It has updated its Be an Energy Shopper website to include key facts and tips around energy supply for tenants.
Ofgem chief executive Dermot Nolan said: "The number of British households renting stands at nine million and counting, yet research has shown that this group is not shopping around for their energy, and missing out on savings of up to £200.
The Be An Energy Shopper campaign spokeswoman Jasmine Birtles said: "It's not just homeowners who can shop around for their energy, renters can too. So it's worth taking a moment to bring yourself up to speed on your rights as a tenant.
"There are substantial savings to be made here so make sure you're not missing out."
:: Ipsos Mori surveyed 1,227 gas consumers and 1,383 electricity consumers between March 7-17.
A Department of Energy and Climate Change spokesman said: "Households could save around £150 a year by switching supplier and we encourage all consumers to shop around for the best deal for their energy bills.
"Energy companies have already confirmed they will halve switching times by the end of the year, but
we want to see them get to 24-hour switching as soon as possible.
"Faster switching is the latest step we're taking to make the energy market work better for consumers, having trebled the number of suppliers since 2010, making people's bills simpler to understand, and plans to introduce QR codes on energy bills to support one-click price comparisons."
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